The Brecon Beacons National Park is only half an hour's drive north of Cardiff, and comprises four mountain ranges and an interesting terrain of old mining valleys, bare escarpments, and sprawling sheep farms.
Most visitors are walkers heading for Offa's Dyke Path, which passes along the eastern border, or the Taff Trail, heading south from Brecon. Offa's Path runs through the Black Mountains, which boast spectacular views including sights such as the ruins of Llanthony Priory, the River Honddu, the ancient hill forts at Y Garn Goch, and the pretty church at Patrishow.
There is much to see and do in Brecon Beacons, and popular activities include hiking, horseback riding, fishing, rock climbing, canoeing, spelunking (cave exploring), and sailing. The popular mountain bike route, the Taff Trail, traces 100 miles (160km) along Beacon's Way across the park. The highest point in the Black Mountains is Waun Fach and the tallest peak in the Brecon Beacons is Pen-y-Fan.
Don't be surprised if you bump into groups of soldiers in the park - this is a major army exercise area and a main training ground for the SAS, who you might see bounding up the mountains, doing the Fan Dance. Around the park are the historic market towns of Brecon and Hay-on-Wye, a fascinating little town with Norman and Jacobean ruins and a famous collection of second-hand book shops.